Achromotrichia due to copper deficiency.

Abstract

A purified diet, similar to diets used in many other laboratories has been employed in this laboratory as a presumably adequate diet for the albino rat. Recently it was observed that black rats on this diet developed an achromotrichia which could be prevented by liver or yeast. Further investigation disclosed that the activity of these substances was due to copper. Achromotrichia due to copper deficiency has been described previously (1–6). In most of these studies the achromotrichia developed on diets composed principally of milk or other crude dietary materials. The present report will describe a type of achromotrichia responding to copper which was produced with a highly purified ration which permitted normal growth and hemoglobin production. Methods. Black, Long-Evans, male rats from the National Institutes of Health colony were housed individually in raised, wire bottom cages and placed on the diets when 21 to 29 days of age with weights of 25 to 59 g. Each group in individual experiments was balanced by litter and weight. The composition of the basal diet 1718B is indicated in Table I. The O&M salt mixture (7) and salt No. 550∗ were prepared in this laboratory following the original instructions. Copper analyses† were by the carbamate method(8). Hematocrits were determined as outlined by Van Allen (9). The degree of grayness was evaluated for each animal on an arbitrary 0 to 4 + scale. To facilitate the comparison of different groups of rats on the same or different diets the plus marks assigned to each rat in a group were totaled and divided by the number of rats in the group to give a Grayness Index. Thus, an index of 4 would represent maximum grayness in every rat.